I'm not sure if you are serious or not....the description itself says that it is 15 watts. There are a couple of hundred LEDs and they only produce 15 watts...oh, and the description says that it is a fluorescent light source. Huh??
Even the cheap Blackstars (which often fail from what I can see by posts on this board) are something like a dollar a watt.
If you were knowledgable, chose carefully and were reasonably skilled at construction, you might be able to make a decent diy LED light for $1/watt...a really good one goes for $2-3+/watt.